Patent GB-678914-A (GB)
Title: Improvements in process and apparatus for the thermal synthesis of carbon compounds
IPC: C01B31/26
Filed: 1948-02-25
Abstract: <PICT:0678914/III/1> An apparatus for use in the thermal synthesis of carbon-containing compounds, e.g. carbon bisulphide, comprises a series of superimposed chambers 11, 12, 13 and 14 connected by unobstructed throats through which fluent solid heat transfer material 10 is caused to flow downwardly as a continuous column and exteriorly from chambers 14 to 11, the material being heated in chamber 11, coated with carbon in chamber 12 and the carbon being reacted with a fluid, e.g. sulphur vapour in chamber 13, balanced fluid pressures being maintained between at least one pair of adjacent chambers by regulating the pressures in chamber 11 and in one of the lower chambers in response to the differential pressure of fluids in the pair of adjacent chambers. The heat transfer material may be small pieces of natural or manufactured refractories or corrosion resistant metals, e.g. spherical pellets of mullite or high alumina refractories.  In operation for the continuous production of carbon bisulphide pellets 10 are heated at 11 by heating gases generated by the combustion of fuel in furnace 18.  In chamber 12 the heated pellets are contacted with and cause dissociation of a hydrocarbon, e.g. propane, the carbon thus formed being deposited on the pellets and hydrogen and unchanged hydrocarbon being passed into furnace 18.  The carbon-coated pellets are then passed into contact (13) with sulphur-vapour formed by vaporization of liquid sulphur introduced through pipe 77 and sprayed downwardly on to the pellets entering cylinder 71.  Carbon bisulphide is formed and withdrawn from chamber 13 through a duct 68 for further processing, storage or immediate use, and the pellets are cooled by direct contact with air in chamber 14, the air thus heated being utilized in furnace 18 for generating heating gases.  The cooled pellets are returned to chamber 11 by means of a feeder 16 and bucket elevator 17.  The cooling chamber may be omitted and the heated pellets returned directly to chamber 11 and instead of separate chambers 11 and 12, the two may be combined into a single chamber with the hydrocarbon being cracked in the lower part thereof and residual hydrogen-containing gas burned by the admission of air for combustion in the upper part.  Leakage of oxygen or air and of fluids between the chambers through the connecting throats is prevented by maintaining delivery of the fluids to the various chambers at superatmospheric pressure and by maintaining balanced pressures between adjacent chambers.  Thus, to prevent leakages of gases between chambers 11 and 12, tubes 96 and 98, which extend into 11 and 12 respectively, are extended to a pressure differential sensitive transmitter 93, which transmits a power impulse to a power element 104 in response to a pressure differential existing across throat 41, with element 104 positioning valve 53 to obtain the required fluid flow through duct 48 to restore balance of pressure.  In a similar manner, transmitters 94, 95, together with their respective power elements 105, 106, which operate valves 90 and 70 respectively, maintain balanced pressures on either side of throats 63 and 80 respectively.  Transmitter 94 is also connected to power element 107 arranged to regulate dampers 31, 34 in stacks 30, 33.